Knitted bed sheet having elastomeric fabric

ABSTRACT

A bedsheet formed from a knitted fabric comprised of two yarn types wherein at least one yarn type is made of an elastomeric fiber and the other yarn type is made of a substantially non-elastic fiber. In the preferred embodiment, one yarn type is a blend of polyester and cotton and the other yarn type is spandex. This overall blend of spandex and poly-cotton fibers creates a knitted fabric having resilience, elasticity and versatility beyond that of a traditional poly-cotton blend fabric. This knitted fabric can then be used to produce sheeting materials, such as fitted contour sheets, which retain shape better, are more easily handled, and have a greater life that standard poly-cotton blend sheets.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application derives priority from U.S. provisional application No. 60/357,186 for “KNITTED BED SHEET HAVING ELASTOMERIC FABRIC”; filed Feb. 19, 2002.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] A knitted fitted bed sheet made from a fabric comprised of two yarn types wherein at least one yarn type is made from an elastomeric fiber, and the other yarn type is made of a substantially non-elastic fiber. In the preferred embodiment, one yarn type is a blend of polyester and cotton and the other yarn type is spandex. This overall blend of spandex and poly-cotton fibers creates a knitted fabric having resilience, elasticity and versatility beyond that of a traditional poly-cotton blend fabric. This knitted fabric is used to produce fitted contour sheets which retain shape better, are more easily handled, and have a greater life than standard poly-cotton blend sheets.

[0004] 2. Description of the Background

[0005] The present invention relates to a fitted contour bed sheet comprised of an improved knitted fabric, and in particular to a knitted sheeting material made of a particular blend of a poly-cotton yarn and elastomeric yarn which retains its shape, is stretchable, versatile, and longer lasting than cotton/polyester sheets.

[0006] Currently, it is known in the art to provide plain woven and knitted sheets to institutions such as hospitals, nursing homes, rest homes and the like. Most commonly, these sheets are woven, rather than knitted, and are made from only a blend of polyester and cotton yarns.

[0007] The fitted or contoured sheets made from “conventional” woven fabric generally do not fit more than one mattress size and are difficult to fit on mattresses having foam comfort overlays. Accordingly, institutions using conventional woven contour or fitted sheets must maintain sheets of several sizes in order to fit all the bed sizes within the institution.

[0008] Another common problem with conventional woven fitted sheets is that they “pop off” the mattress rather easily. Fitted sheets generally pop off the mattress because they are either too small for the mattress or have difficulty adhering to the mattress when the head or foot of the bed is raised or lowered. A common problem associated with conventional sheets that are knitted from polyester-cotton blend strands is that they have a tendency to wear out over time due to “pinholing.” Pinholing results from individual yarns snagging and breaking or from fatigue of fibers due to repeated washing. When the pinholes get too large or too numerous, the sheets are taken out of service. A third problem with conventional woven and knitted contour sheets is shrinkage. After washing they become smaller and thus more difficult to fit over a mattress. The corner seams may rip permanently due to the bed making staff having to pull very hard to stretch the sheets onto the mattress. Finally, in institutional settings, these same prior woven or knitted sheets tend to “bunch” from the raising or lowering of the bed or bunch when a patient repositions one's self in the bed. This bunching can lead to discomfort due to skin shear and pressure points, which is also the common cause of skin problems in older patients.

[0009] U.S. Pat. No. 6,164,092 to the present inventor discloses a fitted bedsheet formed from a knitted fabric comprising two separate yarns, the first being poly-cotton with a fiber content of 55% natural cotton material, and the second being Spandex®. The two yarn strands are knitted together in an overall resulting fabric blend of 90-99.9 weight percent (%) of the poly-cotton, and a range of 0.01-10% of the Spandex®. The yarns are sewn in the form of a fitted bedsheet.

[0010] The present invention improves upon the foregoing bedsheet with a slightly different fabric blend (a lower percentage of natural fiber and higher percentage of synthetic fiber), that has been found through experimentation to increase shape retention, versatility, and useful life over that of the prior art fabric sheets. The particular fabric blend stretches more, and the increased stretching ability allows for easier installation of the fitted sheets on the mattress and allows the creation of one size of fitted sheet to fit all normal sized health care mattresses, with or without foam comfort overlays. The particular fabric blend also allows the sheets to adhere better to the mattress. The particular fabric blend gives the sheets the continued resilience to attempt to “pull” the fabric back into its resting shape even when adhered to the mattress. Further, the elastomeric yarn and poly-cotton yarn blend creates a more resilient fabric, which is resistant to snagging, fiber fatigue, pinholing, and which increases the useful life of the fabric. Further, the elasticity of the present invention allows the sheet to “give” with a patient when the patient is repositioning. Likewise, the elasticity of the sheets allows them to stay taut when the bed is raised or lowered, thereby reducing the occurrence of “bunching up” under the patient. This reduced bunching effect in turn promotes better skin care by reducing skin shear and pressure points.

[0011] In the preferred embodiment, the first yarn type is comprised of a blend of natural and synthetic fibers, preferably a blend of cotton and polyester (hereinafter “poly-cotton”), and the other yarn is comprised of an elastomeric or hyper-elastic fiber such as Spandex®. The poly-cotton strand has a fiber content of between 41% to 50% natural cotton material, and the second being Spandex®. The two yarn strands are knitted together in an overall resulting fabric blend of 90-99.9 weight percent (%) of the poly-cotton, and a range of 0.01-10% of the Spandex®. The yarns are sewn in the form of a fitted bedsheet.

[0012] While the preferred embodiment of this invention addresses problems most associated with fitted or contoured sheets, it is recognized that other products such as crib sheets, pillow cases, stretcher sheets, flat sheets, fitted flat sheets, and sheets for sale to the retail market, may be created from this inventive fabric.

SUMMARY OF THE INVENTION

[0013] Accordingly, it is the principal object of the present invention to provide a fabric which, when made into fitted bed sheets, adheres to a mattress and does not easily pop off when the head or foot end of a mattress is raised or lowered.

[0014] Another object of the present invention is to provide a fabric which can be made into a single size fitted sheet that fits all normal health care mattresses, with or without foam comfort overlays.

[0015] A further objective of the present invention is to provide a fabric which is resistant to snagging, fiber fatigue, and pinholing, which in turn increases the useful life of a sheet, crib sheet, pillowcase, stretcher sheet, or fitted contour sheet made of the fabric.

[0016] It is yet another object of the present invention to increase shape retention, versatility, and useful life over that of the prior art fabric sheets.

[0017] An additional object of the present invention is to provide a fabric which, when made into bed sheets and used in an institutional setting, “gives” with patients' movements when repositioning and stays taut when used as a sheet when the bed is raised or lowered. The ability of the sheets to give and stay taut promotes especially good skin care, and thereby reduces skin sheer and pressure points, which are the most common causes of skin problems in older patients.

[0018] These and other objects and advantages are provided by an improved fitted bedsheet made from a fabric blend that has been found through experimentation to increase shape retention, versatility, and useful life over that of the prior art fabric sheets. The knitted fabric is comprised of two yarn types wherein at least one yarn type is a blend of polyester and cotton and the other yarn type is Spandex. This overall blend of spandex and poly-cotton fibers creates a knitted fabric having resilience, elasticity and versatility beyond that of a traditional poly-cotton blend fabric. This knitted fabric is specifically suited for sheeting materials, such as fitted contour sheets, which retain shape better, are more easily handled, and last longer than standard poly-cotton blend sheets.

[0019] The foregoing and other objects of the present invention will be clarified in the following description of the preferred embodiment in connection with the drawings, the disclosure and the appended claims, wherein like reference numerals represent like elements throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which:

[0021]FIG. 1 is an isometric view of the knitted fabric with the central portion thereof broken away.

[0022]FIG. 2 is an enlarged fragmentary plan view particularly illustrating the elastomeric yarn and poly cotton yarn strands of the sheeting material.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Referring now to the drawings, the knitted fabric 10 of the present invention is illustrated in FIGS. 1 & 2. Although the present invention is directed toward the use of the knitted fabric 10 for bed sheets, and in particular contour fitted bed sheets designed specifically for institutions, it is recognized that the knitted fabric 10 may also be used to make flat sheets, fitted-flat sheets, crib sheets, sheets for sale in the retail market, and for the manufacturing of other sheets.

[0024] In general, the knitted fabric 10 of the preferred embodiment comprises a knitted material having a yarn strand 12, made of a blend of natural and synthetic fibers, and an elastomeric strand or hyper-elastic yarn 14. The yarn strand 12 is knitted together with the elastomeric strand 14 as illustrated in FIG. 2 to create a single piece of textile or knitted fabric 10.

[0025] The novelty of the knitted sheet 10 lies in the fiber content and combination of the two strands of yarn 12 and 14. As seen in FIG. 1, the yarn strand 12 and the elastomeric strand 14 are knitted together to form a single jersey fabric which produces, in one embodiment, a finished sheet measuring approximately 34″.times.71″.times.14″ and weighing between 13 and 30 ounces depending on the over all fabric blend of the elastomeric strand 14 and the yarn strand 12.

[0026] Typically, the yarn strand 12 contains approximately 45.55% natural fiber within a range of from 41% to 50%, and approximately 54.45% synthetic material within a range of from 59% to 50%. It is preferred that the synthetic material be polyester. Likewise, it is preferred that the natural material used in the yarn strand 12 be a combed cotton. Thus, the yarn strand 12 comprises preferably a poly-cotton blend.

[0027] The elastomeric strand 14 of the knitted material may be comprised of any elastic textile fiber, however, it is preferred that the material be made of the elastomeric textile fiber known as Spandex®. Therefore, in the preferred embodiment, the knitted fabric 10 comprises a blend of poly-cotton yarn and spandex.

[0028] As seen in FIG. 2, the fabric is knitted so that there is a 2:1 ratio of elastomeric yarn 14 to poly-cotton yarn 12. While the ratio of elastomeric strands 14 to yarn strands 12 is 2:1, the weight and percentage blend of the poly-cotton yarn to elastomeric yarn is not necessarily a 2/1 ratio. The blend of a finished sheet ranges from 99.9% poly-cotton and 0.01% elastomeric material to 90% poly-cotton and 10% elastomeric material. Accordingly, depending upon the percentage blend of elastomeric yarn 14, the weight of a finished 34″.times.71″.times.14″ sheet can range from 13 ounces to 30 ounces. Because the fabric is knitted with a 1:1 ratio of elastomeric yarn to poly-cotton yarn, the variation between fabric weights and blends are made possible by varying the size of the yarn strand and the denier of the elastomeric strand.

[0029] While the contents of the yarn strand 12 may range from 41% to 50% natural fiber (and 59% to 50% synthetic fiber), it is preferred that the yarn strand 12 be of a size 30/single or finer and made of an intimate blend of 45.5% combed cotton and 54.5% polyester. Likewise, the elastomeric yarn is preferably a size 30/single or finer. This combination of sizes of the yarn strand and elastomeric material produces a 34″.times.71″.times.14″ finished sheet weighing approximately 23.5 ounces that has an overall fabric blend of approximately 41% cotton, 55% polyester, and 4% elastomeric material.

[0030] As discussed above, the weight and blend of the fabric can be easily altered by increasing or decreasing the denier size of the elastomeric strand, increasing or decreasing the size of the yarn strand or increasing or decreasing both the size of the elastomeric strand and the yarn strand. For example, one can increase the weight of the finished sheet and increase the percentage of elastomeric material in the overall fabric blend, by using a larger denier of elastomeric material. However, as stated above it is recommended that overall fabric blends comprise yarn sizes ranging from size 30/single or finer of poly-cotton yarn (the first yarn strand) and ranging from size 30 denier or finer of elastomeric yarn (the second yard strand).

[0031] To manufacture the knitted fabric 10 of the present invention, one may use a standard knitted fabric machine such as a Fukahara Model FXC-3S. To obtain a 1:2 ratio of poly-cotton yarn to elastomeric yarn, the machine is fitted with special feeders such as the Meminger-Iro feeders. These feeders pass the spandex or elastomeric yarn to the knitting bed of the knitting machine. These special feeders are then used in an alternating fashion so that the 2:1 ratio of elastomeric yarn to poly-cotton yarn is feed into the knitting needles.

[0032] Having now fully set forth the preferred embodiment and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims. 

I claim:
 1. A fitted bedsheet formed from a knitted fabric comprising: a first yarn strand comprising poly-cotton fiber formed from approximately 45.55% natural combed cotton fiber within a range of from 41% to 50% and approximately 54.45% polyester within a range of from 59% to 50% a second yarn strand comprising Spandex®; said first and second yarn strands being knitted together in a 2:1 ratio, respectively, to yield an overall fabric blend of from 99.9% poly-cotton and 0.01% elastomeric material to 90% poly-cotton and 10% elastomeric material and a weight of between 13 and 30 ounces for a fitted bedsheet of size 34″ by.71″ by 14″.
 2. A fitted bedsheet formed from a knitted fabric comprising: a first yarn strand comprising poly-cotton fiber having a fiber content of between 41% to 50% natural cotton material; a second yarn strand comprising Spandex; and said first and said second yarn strands being knitted together in an overall resulting fabric blend comprising a range of 90-99.9 weight percent (%) of said first yarn strand, and a range of 0.01-10% of said second yarn strand, and then sewn in the form of a fitted bedsheet.
 3. A bedsheet formed from a knitted fabric as set forth in claim 2 wherein said first yarn strand comprises at least fifty (50%) percent polyester.
 4. A bedsheet formed from a knitted fabric as set forth in claim 2 wherein said first yarn strand contains a blend of approximately 45.55% combed cotton and approximately 54.45% polyester.
 5. A bedsheet formed from a knitted fabric as set forth in claim 3 wherein said first yarn strand is in the range of size 10/single and 30/single.
 6. A bedsheet formed from a knitted fabric as set forth in claim 4 wherein said first yarn strand is at least size 30/single or finer.
 7. A knitted fabric as set forth in claim 1 wherein said second yarn strand is size 30 denier or finer.
 8. A knitted fabric as set forth in claim 1 wherein said second yarn strand is size 30 denier.
 9. A knitted fabric as set forth in claim 1 wherein said first yarn strand and said second yarn strand are knitted together in a 1:2 ratio. 